1. Field of the Invention
This invention relates to a slide fastener, and more particularly to fastener elements for use in a slide fastener with a metallic coating formed on the surface thereof and having a metallic luster.
2. Description of the Prior Art
In the conventional fastener elements for use in slide fasteners, to provide fastener elements having a metallic coating formed on the surface thereof and having a metallic luster or a color tone applicable to highly fashionable sports wears and high-class bags, in case of fasteners elements made of a synthetic resin, fastener elements having a metallic luster are formed by mixing a coloring agent into the synthetic resin, whilst in case of fastener elements made of a metallic material, they have been given a metallic luster by a color tone of the metallic material forming the fastener elements themselves.
However, in the case of fastener elements made of a synthetic resin, since a coloring agent is mixed with a synthetic resin, a metallic luster could not be obtained at the surface of the fastener elements, whilst in the case of metallic fastener elements, since in producing them from a metallic material they are subjected to cutting work, etc., minute irregularities are formed on the surface thereof thereby impairing the metallic luster.
As is well-known, slide fasteners are broadly classified into plastic fasteners using fastener elements made of synthetic resins, and metallic fasteners using metallic fastener elements. The metallic fasteners are disadvantageous in that use of lots of a non-ferrous metal is required, thus rendering the manufacturing cost thereof more expensive than that of the plastic fasteners.
While, the slide fasteners made of a synthetic material are advantageous in that they can be produced at comparatively low costs, and fastener types and fastener elements thereof can be put in any desired color tone which is identical or different from each other, they have come to occupy a substantial proportion of slide fasteners presently in use. However, in spite of the fact that they can be put in any desired color tone, no slide fasteners made of a synthetic resin having a metallic luster are available yet.
Whilst in the field of application to sky wears and high-class bags, in particular in the field of sky wears, light-weight and fashionability are required to pursuit amenity, therefore it has so far been demanded to provide slide fasteners made of a synthetic resin having a metallic luster. To cope with such demands, it has been known to give slide fasteners a color tone which is similar to a metallic luster, either by mixing the synthetic resin with a pigment or by dyeing. However, it is to be regretted that the color tone or luster obtained by such methods has been far from the desired one.